Safety cathead



June 9, 1931. c. R. EDWARDS 1,808,770

I SAFETY CATHEAD I 'Filed Aug. 21, 1925 v 2 Sheets-Sheet l I, I I l gwlor fl zwmz 7 June 9, 1931. c. R. EDWARDS 1,308,770

SAFETY CATHEAD Filed Aug. 21, 1925 2 sheets-sheet 2 v Patented June '9,1931 forms a part of, the conventional draw works UNITED STATES PATENTOFFICE CHARLES R. EDWARDSOF HDUST ON, TEXAS SAFETY GATHEAD Applicationmed August 21, 1925. Serial No. 51,693;

One object of the. invention is to provide a cathead designed to be usedwith, and which used in well drilling operations, and the inventionembodies novel means for operatively connecting the cathead with anddisengaging it from the counter shaft of the draw works.-

Another object of the invention is to produce a device of the characterdescribed which also embodies a one way brake designed to automaticallyoperate to hold the cathead against backward rotation while sustainin aload and when disengaged from said sha whereon it is mounted.

A further feature of the invention resides in the provision of a deviceof the character described embodying a novel type of clutch forclutching the cathead with its shaft for rotation with said shaft, whenthe shaft is rotated in one direction, said clutch permitting theshaftto turn, idly, in the other direction.

With the-above and other objects in view this invention has particularrelation to certain novel features of construction, operation andarrangement of parts, an example of which is given in this specificationand illustrated in the accompanying drawings, wherein j Figure 1 shows aside elevation of the complete device partly in section.

Figure 2 shows a crosssectional view taken on the line 2-2 of Figure 1,

Figure 3 shows a fragmentary side view of the brake employed, and-Figure 4.- shows a fragmentary sectional view. taken on the line 4-4-ofFigure 1.

Referring now more particularly to the drawings, wherein like numeralsof reference designate similar parts in each of the figures, the numeral1 designates the supporting framework of the conventional draw works.The numeral 2 designates the driving counter shaft thereof. Keyed onthis shaft there is a sleeve 3, and loosely mounted on this sleeve thereis the drum like cathead 4, having at its end, adjacentsaid framework,an enlarged annular friction surface 5.

The cathead is retained on the sleeve 3, by means of an internal nut orplug 6 which is threaded into the outer end of said'sleeve and whoseouter end has an annular, outwardly extendin flange 7 which engagesagainst the outsi e of the annular inwardly extending flange 8 carriedby the cathead 4.

There is a long, substantially semi-cylindrical key 9 which is adaptedto lie in a correspondingly shaped keyway 10, in the inner surface ofthe cathead 4 and with its flat face substantially flush with the innersurface of the cathead when completely seated in its keyway. The innerend of this key has a right angular arm 11, preferably integraltherewith, and with its free end 12 inwardl turned and normally heldagainst the sha 2 b means of the pressure spring 13. 1

his spring iscoiled around the set bolt 14, which is anchored to theadjacent end of the cathead, and it has one end anchored to the cathead,with its other end pressing inwardly against the arm 11. The shaft 2 andsleeve 3 normally turn in the direction indicated by the arrow in Figure2, and with the arm 11 lying'against the shaft 2 the key 9 will bepartly unseated from its seat 10, and turned into the opposingsemicylindrical keyway 15 in the outer surface of the sleeve 3, thusforming a clutch and locking the sleeve 3, in driving relation with thecathead 4. Should the shaft 2 be reversed the sleeve 3 will run idlywith relation to the cathead, on the pl nciple similar to that of theconventional er clutch. I

There is a clutch releasing'mechanism embodying a loosely mounted collar16, slidable on the shaft 2 and having the tapering faces,

as 17. This collar. is operatively connected with a yoke 18 which ispivoted to the framework and extended, forming the lever 19.

17 will engage under the outturned end 12 of the arm 11 and hold thesame away from the shaft 2 and thus fully seat the key 9 in its seat 10and permit the sleeve 3 to turn idly in the cathead. By depressing theouter end of the pedal 20, the collar 16 may he released from the arm 11and the pressure of the spring 13 will cause the key 9 to rise from itsseat into interlocking position with the sleeve 3. I

Various kinds of work is done with the cathead in drilling operations.In carrying I out this work a cable. is wound around the cathead and oneend attached to a load to be lifted, or other-work to be performed. Theouter end of the cable is held, and manipulated, by a workman in theusual way. It sometimes happens that the cathead is released from itsshaft while sustaining a load. In order to hold it, to prevent droppingof the load, there'is provided a friction brake.

embodying a band -23 which surrounds the friction surface 5, and alsoincluding a lever 2d, ivotd to the bracket 25, which is attached to t eframe 1. The respective ends of the band 23 are attached, one to thefree end of the lever 24 and the other at an intermediate 1 end thereof,and a fiat, pressure sprin 26 is 2 load sustained by arranged to pressagainst said lever an tends to tighten the band 23 around the frictionsurface 5 so as to hold the band in readiness to be frictionally engagedand gripped by the friction surface 5, of the cathead, in casethecathead isdeclutched from the shaft 2- and starts to turn, under theinfluence of the it. The cathead will thus be held against reverserotation.

7 There are obviousl man mechanical variations which may e ma e in theconstruction of the device and other combina tions in which it may beused, besides its use in connection with draw works.

What I claim'isz- V 1. In a safety device, a cathead, means adapted tosupport and to drive said cathead,

said cathead being adapted to receive and drive a line by friction whilesaid line is nsoawo ating line and normally revolvable inone directiononly, a driving member to rotate the cathead, engaging means for drivingsaid cathead, through said driving member, means through which anoperator may hold said engaglng means engaged while said cathead isbeing revolved and while said line is being operated on said cathead.

4. In a safety device, a cathead to receive- CHARLES 1t EDWARDS.

' manually held in contact with said cathead,

. engaging means whereby said catheadma V be driven in only onedirection, means throng which said engaging means maybe held in engagingposition by the operator while me nipulating the line, and meanspreventing -a reverse rotation of said cathead,

2. In a safety device, a support, a cathead adapted to operate or hold aline as said line is manipulated into only a frictional contacttherewith, a driving member, operative en gaging means whereby said.cathead ma driven In only one direction by said riv ingnmember onlywhen-said means is held by a e manipulator and means gpreventing areverse rotation of said catheao.

3. In a safety device, a support, a cathead on the snpport and adaptedto receive anciper' j

